We came across a bug (or gotcha?) that if you send a File object representing JSON, with the Content-Type application/json it will invoke .toJSON(), yielding a body such as the following: {"webkitRelativePath":"","lastModifiedDate":"2013-04-25T21:45:17.000Z","name":"package.json","type":"application/json","size":265,"kind":"file"} This seems pretty incorrect as any other type of file would pass through appropriately.
Oh no this may be our request lib, I'll re-open if I can confirm the issue stand-alone.